Computers are used in just about every business and government organization. Computers perform many services, such as aiding in word processing, controlling complex equipment, and storing and accessing large databases. As more information, software, and confidential information are stored on computers, a need arises to protect this information from unauthorized access.
One way of preventing access to the information is to restrict access to the computers. Several methods are used to prevent unauthorized access, such as locking the computers in a separate room, covering or locking the keyboard and/or mouse when the operator is not present, or installing a key switch in the cable leading from the keyboard to the computer. While preventing unauthorized access, these methods suffer from several disadvantages. Providing a secure room is not always feasible do to lack of space or inconvenience of operation. Mechanical devices are cumbersome, and take time and effort to use. In addition, the devices are not used when the operator only plans to be away for a brief period of time.
Another method to restrict access to a computer is to provide a password system in the computer's software. Password protection is the most common method used to prevent unauthorized access to computers and sensitive electronics. The sophistication of the password protection software is selected based on the sensitivity of the information that is being protected. The most sophisticated software, however, can be defeated if the unauthorized user has the password.
The desire to infiltrate these systems has led to the development of in-line listening devices. The in-line listening devices are inserted in-line with an input device, such as between the keyboard DIN connector and the mating connector on the computer. When the operator enters her password to access the computer, the in-line listening device intercepts and stores the password. The unauthorized intruder later removes the listening device and retrieves the password. To combat the threat of in-line listening devices, “high security” systems monitor the input connection to the computer. If the connection is interrupted at any time before the operator logs on to the system the operator is alerted to the interruption of the connection, and the possible breach of security.
Software monitoring of the input device connection, however, does not provide sufficient protection to prevent in-line listening devices from being installed. Operators often dismiss the notification if the message is displayed frequently. For example, if the input connector is disconnected and reconnected on a nightly basis most operators will stop inspecting the connection and simply dismiss the security alert as a computer error. After a brief time, the in-line listening device can be inserted without the threat of detection.
As a result, there exists a need to solve the aforementioned deficiencies in the prior art, that is low cost, readily adaptable to existing computers, and easy to install.